What Is C11-15 Pareth-15?
C11-15 Pareth-15 is a non ionic surfactant made by attaching an average of 15 ethylene oxide units to a chain of synthetic or plant derived fatty alcohols that contain 11 to 15 carbon atoms. This process, called ethoxylation, takes place under heat and pressure with a basic catalyst until the desired chain length is reached. The result is a waxy or thick liquid that dissolves easily in water and oil, making it highly versatile in cosmetic formulas.
The ingredient was introduced to personal care labs around the 1960s when chemists looked for gentle alternatives to traditional soaps. Its balanced oil and water affinity allowed formulators to create clear, mild cleansers at lower irritation potential than sulfated surfactants. As consumer demand for sulfate free and lightweight textures grew, C11-15 Pareth-15 found its way into facial washes, shampoos, micellar waters, makeup removers, body washes, leave-on lotions, anti aging serums, moisturizers, sheet masks and cleansing wipes.
C11-15 Pareth-15’s Cosmetic Benefits/Uses
This multifunctional ingredient supports both the texture and performance of modern skin and hair care.
- Cleansing: Its surfactant nature loosens and lifts dirt, excess oil and makeup so they can be rinsed away without leaving skin tight or hair squeaky
- Emulsifying: Helps blend oil and water phases, keeping creams, lotions and serums stable with a smooth, non greasy feel
Who Can Use C11-15 Pareth-15
C11-15 Pareth-15 is generally well tolerated by all skin types including normal, oily, combination, dry and mature skin. Its mild cleansing action and low tendency to strip natural oils make it a good match for sensitive skin too, though those with highly reactive skin should still pay attention to overall formula strength and supporting ingredients.
The material can be sourced from either synthetic routes or plant derived fatty alcohols so it is suitable for vegans and vegetarians when the finished product specifically states plant origin.
Current safety assessments show no evidence that the ingredient poses a unique risk during pregnancy or breastfeeding when used in rinse off or leave on cosmetics. This is not medical advice and pregnant or nursing individuals should share any planned skincare routine with a healthcare professional to be safe.
C11-15 Pareth-15 does not make skin more sensitive to the sun and there are no known interactions with common active ingredients such as retinoids or vitamin C.
Potential Side Effects/Adverse Reactions
Responses to topical C11-15 Pareth-15 can vary from person to person. The points below describe potential but uncommon effects; most people will not notice any problems when the ingredient is used at standard cosmetic levels.
- Temporary stinging or redness if applied to broken or highly irritated skin
- Mild eye irritation if a product containing it accidentally gets into the eyes
- Very rare cases of contact dermatitis in individuals with pre existing surfactant sensitivities
If you experience any persistent discomfort stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1/5
C11-15 Pareth-15 is a water soluble surfactant that rinses off cleanly so it does not sit on skin or clog pores. Formulas typically use it in low amounts for cleansing or to keep oil and water mixed which further reduces any risk of buildup. For these reasons it earns a low comedogenic rating of 1.
Suitable for acne prone and breakout prone skin under normal use.
No special storage or handling issues affect its pore clogging potential. Any finished product is more likely to cause breakouts because of heavier emollients or occlusive agents in the recipe, not because of C11-15 Pareth-15 itself.
Summary
C11-15 Pareth-15 works as a gentle cleanser and an emulsifier. Its balanced water and oil loving parts surround dirt and oils so they rinse away easily while also keeping creams and lotions smooth and uniform.
The ingredient is popular in clear gels micellar waters and lightweight lotions but you will find it less often in thick rich creams that rely on heavier emulsifiers. Its mildness and versatility keep it in steady use by formulators even if it is not a headline selling point on product labels.
Current research shows it is safe for all skin types at the levels used in cosmetics. Still try a small patch when trying any new product to be sure it suits your individual skin.